Electrical Transport from 5 K- 300 K in Fe₂O₃@CNT Hybrids

Abstract

α-Fe₂O₃ (hematite) is a transition metal oxide with antiferromagnetic ordering and potential applications in energy storage and photocatalysis. In Fe₂O₃@CNT composites, carbon nanotubes provide conductive pathways while hematite introduces magnetic functionality, forming a coupled hybrid system. This thesis investigates the structural and temperature-dependent electrical transport properties of Fe₂O₃@CNT composites to understand how magnetic ordering in hematite influences conduction in CNT networks. Structural characterization using XRD, Raman spectroscopy, and FESEM confirms the presence of crystalline α-Fe₂O₃ integrated within aligned multiwalled CNT structures. Electrical transport measurements from 5 K to 300 K show overall semiconducting-like behavior with clear anomalies in the 150–300 K range, corresponding to the Morin transition of hematite nanoparticles. Arrhenius and Variable Range Hopping analyses suggest that no single transport mechanism fully explains the observed behavior. The results indicate that transport in Fe₂O₃@CNT composites arises from multiple competing mechanisms involving hopping conduction, CNT network transport, magnetic transitions, and interfacial strain effects.